Photos: Prolonged low tides see smaller canals dry up in Venice

Venice: Gondolas lay beached along a series of Venice's famed canals this week, as low tides and a lack of rain left would-be punters high and dry.

Tourists out on the deeper, busier canals sailed passed exposed foundations of ancient palazzos in the UNESCO World Heritage Site, while in shallower ones, forlorn boats sat on silty mud flats.

While the Italian city is better known for its high tides, which regularly flood St Mark's Square, it is also affected by low tides, which can make life difficult not only for holiday makers but for water ambulances.

The prolonged stretch of ebb tides is linked to a lingering high-pressure weather system over much of Italy, experts say.

"It's an absolutely normal phenomenon," said Alvise Papa, the head of Venice's tide forecasting centre. "Low tides are not enough to dry up the canals, but this year they are accompanied by high atmospheric pressure, which prevents bad weather", he said.

In mid-winter, high atmospheric pressure combined with the lunar cycle produces the ultra-low water levels during ebb tide, noted Jane Da Mosto, an environmental scientist and sustainable development analyst with We Are Here Venice, an environmental advocacy group.

She added that the phenomenon highlights lack of attention to the overdue need for cleaning Venice's inner canal network. Navigation continued on the wider, main waterways, including the Grand and Giudecca canals.

Separately, the same high pressure system compounded by scarce Alpine snow melt this year has been a factor for the shriveling of lakes and rivers in northern Italy in recent weeks.

This month, an isthmus linking the shores of Lake Garda to a small island has re-emerged, delighting visitors who were able to, in effect, walk part-way across the middle of the lake.

Boats are pictured in a canal during a severe low tide in the lagoon city of Venice, Italy.